Process control systems, like those used in chemical, petroleum or other processes, typically include one or more process controllers communicatively coupled to one or more field devices via analog, digital or combined analog/digital buses. The field devices, which may be, for example, valves, valve positioners, switches and transmitters (e.g., temperature, pressure and flow rate sensors), perform process control functions within the process such as opening or closing valves and measuring process control parameters. The process controllers receive signals indicative of process measurements made by the field devices and then process this information to generate control signals to implement control routines, to make other process control decisions, and to initiate process control system alarms.
Information from the field devices and/or the controller is usually made available over a data highway or communication network to one or more other hardware devices, such as operator workstations, personal computers, data historians, report generators, centralized databases, etc. Such devices are typically located in control rooms and/or other locations remotely situated relative to the harsher plant environment. These hardware devices, for example, run applications that enable an operator to perform any of a variety of functions with respect to the process of a process control system, such as viewing the current state of the process, changing an operating state, changing settings of a process control routine, modifying the operation of the process controllers and/or the field devices, viewing alarms generated by field devices and/or process controllers, simulating the operation of the process for the purpose of training personnel and/or evaluating the process, etc.
These hardware devices typically include one or more operator interface displays to display pertinent information regarding the operating state(s) of the control system(s) and/or the devices within the control system. Example displays take the form of alarming displays that receive and/or display alarms generated by controllers or devices within the process control system, control displays that indicate the operating state(s) of the controller(s) and other device(s) within the process control system, etc.
In a process control system it is common for thousands of alarms to be defined within the process control system to notify operators of the process control system of potential problems. Alarms are defined, for example, to protect people and/or equipment, to avoid environmental incidents, and/or to ensure product quality during production. Each alarm is typically defined by one or more settings (e.g., an alarm limit) that define when a problem has occurred and/or trigger the alarm, and a priority (e.g., critical or warning) to define the importance of the alarm relative to other alarms.
Typically, alarms are presented (e.g., displayed) to operators in list or tabular format. In such formats, each alarm is presented as a single line in the list with specific data that may be relevant to inform an operator of the state of the control system. Data provided in an alarm list may include, for example, a description of the alarm, the time the alarm was triggered, the source of the alarm, the importance or priority of the alarm, the state of the alarm (e.g., acknowledged or not, active or not), the parameter that triggered the alarm, the value of the parameter, etc. As information is received from process controllers and/or field devices, the alarm list data may be updated in real time to allow the operators access to current information regarding all active alarms.